MediumCVE-2025-21859

    Linux Kernel: Deadlock (CVE-2025-21859)

    Published Last modified Sources: Siemens ProductCERT, BSI, SUSE, Debian LTS, Debian, CVE.org, Msrc Update Guide, EUVD

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: USB: gadget: f_midi: f_midi_complete to call queue_work When using USB MIDI, a lock is attempted to be acquired twice through a re-entrant call to f_midi_transmit, causing a deadlock. Fix it by using queue_work() to schedule the inner f_midi_transmit() via a high priority work queue from the completion handler.

    Update Linux Kernel to version 5.4.291, Linux Kernel to version 5.10.235, Linux Kernel to version 5.15.179.

    Affected
    • Linux Kernel lt 3.2..5.4.291
    • Linux Kernel lt 5.5..5.10.235
    • Linux Kernel lt 5.11..5.15.179
    • Linux Kernel lt 5.16..6.1.130
    • Linux Kernel lt 6.2..6.6.80
    • Linux Kernel lt 6.7..6.12.17
    • Linux Kernel lt 6.13..6.13.5
    Fixed in
    • Linux Kernel 5.4.291
    • Linux Kernel 5.10.235
    • Linux Kernel 5.15.179
    • Linux Kernel 6.1.130
    • Linux Kernel 6.6.80
    • Linux Kernel 6.12.17
    • Linux Kernel 6.13.5
    • Linux Kernel 6.14

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: Siemens ProductCERT, BSI, SUSE, Debian LTS, Debian, CVE.org, Msrc Update Guide, EUVD

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 8.8

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    36.28 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.2 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    8.8
    Low — this CVE sits in the lower 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 1 October 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-667

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    In the Linux kernel, the following vulnerability has been resolved: USB: gadget: f_midi: f_midi_complete to call queue_work When using USB MIDI, a lock is attempted to be acquired twice through a re-entrant call to f_midi_transmit, causing a deadlock. Fix it by using queue_work() to schedule the inner f_midi_transmit() via a high priority work queue from the completion handler.

    Source: siemens_advisory, BSI CSAF, BSI WID Portal, suse_csaf, Debian LTS Advisories, Debian Security Advisories, cvelistv5, NVD (NIST), Microsoft Security Update Guide, CVE.org (MITRE), ENISA EUVD

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    LinuxLinux
    • 6.7 – < 6.12.17
    • 5.5 – < 5.10.235
    • 5.16 – < 6.1.130
    • 6.2 – < 6.6.80
    • —
    • 3.2 – < 5.4.291
    • 5.11 – < 5.15.179
    • 6.13 – < 6.13.5
    • 6.12.17
    • 5.10.235
    • 6.1.130
    • 6.6.80
    • 6.14
    • 5.4.291
    • 5.15.179
    • 6.13.5
    DellSecure Connect Gateway
    • < 5.30.0.14
    • 5.30.0.14
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxbullseye
    Linuxdebianlinux-6.1bullseye
    Linuxlinuxlinux_kernel6.14
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-667Improper Locking

      Class

      The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

      Entry at MITRE CWE-667

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/1f10923404705a94891e612dff3b75e828a78368
      Referenceadded
      —
      https://git.kernel.org/stable/c/24a942610ee9bafb2692a456ae850c5b2e409b05
      Referenceadded
      —
      https://git.kernel.org/stable/c/4ab37fcb42832cdd3e9d5e50653285ca84d6686f
      Referenceadded
      —
      https://git.kernel.org/stable/c/727dee0857946b85232526de4f5a957fe163e89a
      Referenceadded
      —
      https://git.kernel.org/stable/c/8aa6b4be1f4efccbfc533e6ec8841d26e4fa8dba
      Referenceadded
      —
      https://git.kernel.org/stable/c/b09957657d7767d164b3432af2129bd72947553c
      Referenceadded
      —
      https://git.kernel.org/stable/c/deeee3adb2c01eedab32c3b4519337689ad02e8a
      Referenceadded
      —
      https://git.kernel.org/stable/c/e9fec6f42c45db2f62dc373fb1a10d2488c04e79
      Referenceremoved
      https://git.kernel.org/stable/c/1f10923404705a94891e612dff3b75e828a78368
      —
      Referenceremoved
      https://git.kernel.org/stable/c/24a942610ee9bafb2692a456ae850c5b2e409b05
      —
      Referenceremoved
      https://git.kernel.org/stable/c/4ab37fcb42832cdd3e9d5e50653285ca84d6686f
      —
      Referenceremoved
      https://git.kernel.org/stable/c/727dee0857946b85232526de4f5a957fe163e89a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8aa6b4be1f4efccbfc533e6ec8841d26e4fa8dba
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b09957657d7767d164b3432af2129bd72947553c
      —
      Referenceremoved
      https://git.kernel.org/stable/c/deeee3adb2c01eedab32c3b4519337689ad02e8a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/e9fec6f42c45db2f62dc373fb1a10d2488c04e79
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1f10923404705a94891e612dff3b75e828a78368 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/24a942610ee9bafb2692a456ae850c5b2e409b05 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/4ab37fcb42832cdd3e9d5e50653285ca84d6686f Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/727dee0857946b85232526de4f5a957fe163e89a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/8aa6b4be1f4efccbfc533e6ec8841d26e4fa8dba Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b09957657d7767d164b3432af2129bd72947553c Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/deeee3adb2c01eedab32c3b4519337689ad02e8a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/e9fec6f42c45db2f62dc373fb1a10d2488c04e79 Types: Patch
      —

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    2. Record modifiedCVE Program

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
      Referenceadded
      —
      https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
      Referenceremoved
      https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
      —
      Referenceremoved
      https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
      —

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    3. Record modifiedSiemens ADP

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/21xxx/CVE-2025-21859.json">CVE-2025-21859</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-265688.html
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html
      Referenceremoved
      https://cert-portal.siemens.com/productcert/html/ssa-265688.html
      —

      Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

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